JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2017
·
IF 2.269
Kai Huang,Tao Zhang,Bo Jiang,Wanmeng Mu,Ming Miao
l -Ornithine, a non-protein amino acid, is widely used as a food supplement and nutrition product that is usually produced by the enzymatic hydrolysis of l -arginine. However, urea, a by-product, complicates purification of l -ornithine. Here, we describe a highly efficient coupled system, which involves Rummeliibacillus pycnus arginase and Jack bean urease, for the production of l -ornithine without urea residue. Although R. pycnus arginase exhibited the highest enzyme activity at pH 9.5 with Mn 2+ , it could be activated by Ni 2+ at 70 °C and pH 6.5. Kinetic study showed that, compared with Mn 2+ -containing arginase, Ni 2+ -containing arginase had a higher substrate affinity and catalysis efficiency. Based on the properties of commercial Jack bean urease and recombinant arginase, both enzymes showed robust activity at pH 6.5 and 40–50 °C. Using a coupled system involving arginase and urease for bioconversion, l -ornithine production of 37.8 g l −1 was achieved with a 99.7% molar yield within 5 h. Thus, this coupled system represents an applicable strategy for the biosynthesis of l -ornithine.
研究领域:
生物化学
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酶工程
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生物技术
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
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IF 5.7
Weijie Gao,Zijian Jing,Yifang Meng,Qinghai Liu,Hualei Wang,Dongzhi Wei
Lysine cyclodeaminase (LCD)-mediated synthesis of l-pipecolic acid (l-PA) from l-lysine (l-Lys) is a promising approach. However, only one LCD has been reported, and its inadequate activity limits industrial applications. To address this problem, a substrate analogue-guided enzyme mining strategy was employed. A novel ornithine cyclodeaminase (OCD) from Rhizobium leguminosarum (RlOCD) was identified in combination with directed macrogenomic approaches. RlOCD displayed a conversion rate of 28% at a substrate loading as high as 1000 mM. A multiregion synergy strategy consisting of pocket reshaping, dynamical cross-correlation matrix-guided coevolutionary design, and surface modification was used to design RlOCD from the inside-out. A quadruple mutant (V93C/L119C/I170T/R90L) designated Mu4 with significantly increased activity was obtained, which showed a 28.46-fold increase in the catalytic efficiency. The conversion of Mu4 was 91% within 10 h at 1000 mM (146.19 g L–1) loading. The space–time yield of 282.1 g L–1 d–1 is the highest level ever reported. Molecular dynamics simulations and interaction analyses revealed that efficient pocket expansion and unique conformational rearrangements increased the affinity for the substrate, resulting in a more catalytically active conformation. This study expands the toolbox for the production of l-PA and demonstrates the effectiveness and potential of Mu4 for its production.
研究领域:
生物化学
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酶工程
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合成生物学
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产品关联
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
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2020
·Vol. 104
·期 15
·6635-6646
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IF 3.53
Huang Kai,Zhang Shurong,Guan Xiao,Liu Jing,Li Sen,Song Hongdong
This study aims to use neutral pH optimum arginase as the catalyst for high-efficiency l -ornithine production. Sulfobacillus acidophilus arginase was firstly cloned and overexpressed in Escherichia coli . The purified enzyme was obtained, and the molecular mass determination showed that this arginase was a hexamer. S. acidophilus arginase possessed similarities with the other arginases such as the conserved sequences, purification behavior, and the necessity for Mn 2+ as a cofactor. The maximum enzyme activity was obtained at pH 7.5 and 70 °C. Thermostability and pH stability analysis showed that the arginase was stable at 30–60 °C and pH 7.0–8.5, respectively. The kinetic parameters suggested that S. acidophilus arginase could efficiently hydrolyze l -arginine. Bioconversion with this neutral pH optimum arginase had the advantages of avoiding producing by-product, high molar yield, and high-level production of l -ornithine. When the bioconversion was performed with a fed-batch strategy and a coupled-enzyme system involving S. acidophilus arginase and Jack bean urease, the final production of 2.87 mol/L was obtained with only 1.72 mmol/L l -arginine residue, and the molar yield was 99.9%. The highest production record suggests that S. acidophilus arginase has a great prospect in industrial l -ornithine production.
研究领域:
生物技术
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酶学
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微生物学
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生物化工
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DOI
PubMed
高影响因子
RSC Advances
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2017
·Vol. 7
·期 52
·32786-32794
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IF 3.108
Jingqian Fan,Yuangang Liu,Shibin Wang,Yulu Liu,Siming Li,Ruimin Long,Ran Zhang,Ranjith Kumar Kankala
Layer-by-Layer (LbL) self-assembly of nanocarriers has garnered the interest of researchers for a wide variety of biomedical applications. In this study, we demonstrated the preparation of poly(lactide-co-glycolide) (PLGA)-(poly-L-ornithine (PLO)/fucoidan)4 core–shell nanoparticles (LbL NPs) by a LbL-based self-assembly process, which possessed a mean size of 170 nm. In LbL NPs, a drug carrying PLGA nano-core is coated with alternating PLO and sulfated polysaccharide fucoidan composite films as a shell on the surface. The anti-tumor drug doxorubicin (DOX) loaded into the PLGA core, resulted in better encapsulation efficiency and its in vitro release from LbL NPs demonstrates that this core–shell strategy takes an advantage of its ability to hold the drug cargo and exhibit controlled release. Further, in vitro cell uptake studies by confocal laser scanning microscopy (CLSM) examination in breast tumor cells (MCF-7 cell line) have confirmed that the nanocarriers are successfully internalized and outlined their presence in the cytoplasm after 4 h of incubation. These intracellularly delivered DOX-loaded LbL NPs exhibited significant anti-tumor activity against breast tumor cells. This innovative chemotherapeutic design taking above advantages of successful internalization along with controlled release property signifies as a promising interventional therapeutic delivery system.
研究领域:
药剂学
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生物材料
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肿瘤学
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DOI
高影响因子
ANALYST
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2012
·Vol. 137
·期 18
·4235-4240
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IF 4.23
Xiaoyu Mu,Li Qi,Ying Shen,Haizhi Zhang,Juan Qiao,Huimin Ma
A novel amino acid ionic liquid (AAIL) with L-ornithine (L-Orn) as anion was successfully synthesized, and subsequently applied as an available chiral ligand coordinated with Zn(II) in a chiral ligand exchange capillary electrophoresis (CLE-CE) system for the enantioseparation of dansyl amino acids (Dns-D,L-AAs). The influence of key parameters, such as buffer pH, concentration ratio of Zn(II) to ligand and complex concentration, was investigated in detail. Eleven pairs of Dns-D,L-AAs enantiomers were baseline separated and three pairs were partly separated under the optimum conditions. For exploring its potential application, the quantitative features of this proposed method were studied. Good linearity (r2 = 0.999) and favorable repeatability (RSD ≤ 3.4%) were obtained by using Dns-D,L-Met as the test analyte. Finally, this method was employed to investigate the inhibition efficiency of D-amino acid oxidase (DAAO) inhibitors, which may pave a new way for the high-throughput screening of enzyme inhibitors and relevant drug discovery.
研究领域:
分析化学
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药物分析
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酶学
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手性分离
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药物发现
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代谢酶
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DOI
高影响因子
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY
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2014
·Vol. 20
·期 1
·109-121
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IF 3.164
Zhang Zhongyu,Bi Caifeng,Fan Yuhua,Zhang Nan,Deshmukh Rahul,Yan Xingchen,Lv Xiuwen,Zhang Pengfei,Zhang Xia,Dou Q. Ping
Abstract Ubiquitin–proteasome system (UPS) plays a crucial role in many cellular processes such as cell cycle, proliferation and apoptosis. Aberrant activation of UPS may result in cellular transformation or other altered pathological conditions. Previous studies have shown that metal-based complexes could inhibit proteasome activity and induce apoptosis in certain human cancer cells. In the current study, we report that the cadmium and copper complexes with heterocycle-ornithine Schiff base are potent inhibitors of proteasomal chymotrypsin-like (CT-like) activity, leading to induction of apoptosis in cancer cells. Two novel copper-containing complexes and two novel cadmium-containing complexes with different heterocycle-ornithine Schiff base structures as ligands were synthesized and characterized. We found that complexes Cu1, Cd1 and Cd2 show proteasome-inhibitory activities in human breast cancer MDA-MB-231 and human prostate cancer LNCaP cells, resulting in the accumulation of p27, a natural proteasome substrate and other ubiquitinated proteins, followed by the induction of apoptosis. Our results suggest that metal complexes with heterocycle-ornithine Schiff base have proteasome-inhibitory capabilities and have the potential to be developed into novel anticancer drugs. Graphical Abstract
研究领域:
化学
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肿瘤学
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分子生物学
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药理学
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DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2021
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IF 7.514
Peng Yang,Guixia Zhong,Juanchun Yang,Linyu Zhao,Ding Sun,Yaqin Tian,Ruren Li,Liangyan Rong
Understanding the interrelationships between the differentially abundant microorganisms and metabolites of traditional “Fuet” fermented sausages (FSs) and inoculated fermented sausages (IFSs) can help us identify key species that are missing from commercial starter cultures to reproduce the flavor compounds and nutrients of traditional Fuet FSs. IFSs, inoculated with P. pentosaceus , P. acidilactici , S. xylosus , S. carnosus (SBM-52) or P. pentosaceus , and S. xylosus (THM-17), were deficient in reproducing the volatilome profile (in particular esters, methyl aldehydes, and methyl ketones) of traditional Fuet FSs because of the lack of diverse Staphylococci ( S. carnosus , S. xylosus , S. equorum , and S. saprophyticus ). Moreover, the combination of Pediococcus and Staphylococcus were positively associated with amino acid, fatty acid, l -anserine, and l -carnosine levels. Pyridoxal and indolelactic acid levels were significantly increased in IFSs with the addition of P. acidilactici and S. carnosus , which were positively associated with vitamin B 6 and tryptophan metabolic pathways.
研究领域:
食品科学
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微生物学
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代谢组学
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营养学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）